Currently wireless cell phones are used throughout the world and their use is rapidly expanding. Cell phones operate in combination with antenna cell sites that are positioned throughout a reception area to provide optimum coverage. When designing a cell site for a wireless cell communication system, the physical position and the pointing direction of a cell antenna is an important parameter in defining the cell site coverage. Therefore, many cell antennas are installed on top of buildings or on towers to extend the cell site coverage area. To install cell antennas in an outdoor environment, the antennas are mounted on top of a supporting pole installed at each cell site. To install cell antennas in an indoor environment, the antennas are mounted on a wall or ceiling. In both cases, clamping tools are used to secure the placement of the antennas.
Antenna clamping tools are used to firmly install the cell antennas on a wall or an existing structure. Installation or adjustment of antennas is not only very dangerous for technicians, as it requires the technicians to climb up to a tall tower or onto a roof and to use both hands for a long period of time, but is also very tedious, which is costly because the technicians have to repeat many of the same procedures over and over again when adjusting the antenna for optimum reception.
A typical prior art antenna beam controlling assembly is shown in FIGURE A and is comprised of five major elements: a cell antenna 10, an antenna mounting pole 18, an upper articulated mounting bracket 30, an upper clamp 24 and a lower clamp 26. The cell antenna 10 has internal reflectors (not shown) for sending and receiving RF signals and includes an upper end 12 and a lower end 14. The mounting pole 18 has an upper end 20 and a lower end 22. To the pole's upper end 20 is attached an upper clamp 24, and to the pole's lower end 22 is attached a lower clamp 26. The upper articulated mounting bracket 30 has an outer end 32 and an inner end 34. The outer end 32 is attached to the upper end 12 of the antenna 10, and the inner end 34 is attached, via the upper clamp 24, to the upper end 20 of the mounting pole 18, as shown in FIGURE A. The lower end 14 of the antenna 10 is attached via a lower clamp 26 to the lower end 14 of the antenna 10.
The installation procedure of the prior art antenna beam controlling assembly is comprised of the following steps: first, loosen a pair of nuts located on the upper clamp 24 and the lower clamp 26, which widens the space of the two clamps.
Second, adjust the lower clamp 26 to support the pole 18 and control the direction angle by rotating the antenna 10 along a known direction of an electromagnetic wave corresponding to a cell sector.
Third, loosen a pair of bolts located on the articulated mounting bracket 30 and move along the folding or the unfolding direction of the articulated mounting bracket 30 to adjust the antenna's downward tilt angle. After adjusting the downward tilt angle, tighten the pair of bolts to secure the antenna. The amount of downward tilt required for the antenna 10 is determined by reading a notch mark 36 on an angle indicator 38 located on a side of the articulated mounting bracket 30.
There has recently been a demand to change the direction of cellular antenna beams, due to changes of the topography around a cell site or the degradation of call quality in dense traffic areas. In addition, because there is usually another cell site closely situated, the interference level with other cell sites should be considered when deciding the location of a cell site. In other words, the different conditions of all cell sites should be taken into consideration. In particular, with respect to the horizontal azimuth angle (i.e., horizontal steering), the electrical horizontal beam steering, which controls the phase of signals transmitted to radiating elements, would change the direction of the beam. As a result, scan loss would occur and the sidelobes would be increased. Therefore, in case of horizontal steering, it would be effective to mechanically control the direction of the beam by rotating the antenna itself either to the right or left. In case of electrical control, the antenna must consist of at least two columns of a radiating-element-array. However, there have been some negative issues such as increased width/size of the antenna, increased design complexity, increased weight of the antenna, or an increase in manufacturing costs of the antenna products.
With the existing wireless communication cell site antenna system discussed above, it is difficult to change the direction of the antenna beam frequently because a person needs to manually adjust the antenna and therefore there is always a danger of an accident.
Recently, clamping systems have also been installed on the outside of the antenna and thus combined with the supporting mounting pole. This type of installation requires a larger space for the antenna system and does not offer a zoning friendly appearance. Vertical down-tilting, which comprises electric down-tilting by means of a phase-shifter, could maintain the shape of horizontal beams, and mechanical down-tilting could control the center part of the horizontal beams but could not effectively control the side parts of the horizontal beam shape. Therefore, electrical down-tilting is more effective.
The instant invention solves and/or eliminates many of the problems discussed above that are inherent in the prior art.
A search of the prior art patents and industry literature did not disclose an antenna beam controlling system that read on the claims of the instant application.